The invention relates to a digital phase-locked loop.
In communication technology there is often the problem of synchronizing the frequency and phase of an oscillator with a reference signal. To solve the problem, so-called phase-locked loops are used. One distinguishes analog phase-locked loops working with analog signals, and digital phase-locked loops working with discrete-time and/or discrete-value signals within the control loop.
U.S. Pat. No. 4,107,623 has disclosed a phase-locked loop for synchronizing the frequency and phase of an oscillator with that of a reference oscillator. The arrangement comprises an analog control loop for fine adjustment and a digital control loop for coarse adjustment of the frequency of the oscillator signal. The use of the digital phase-locked loop makes it also possible to work with large phase differences between the two oscillators that are to be synchronized.